overheating?

[red eye]

While playing rage my pc restarted, this has happened twice today prob 30-to an hr play. last night it was fine, I can hear fan rpm increase im guessing that is the gpu. any ideas?

this is a new build and I just installed the gpu yesterday
specs are asus p8z68v I used the ez menu to overclock the i5 2500k to 3.4ghz and the 1600mhz ram to 1648mhz power supply is antec ture power 650w gpu is msi 6950 twin frozr 3 2gb.

 

[red eye]

I know, it was asus quick oc thing in bios I was waiting on gpu and then overclock in a few months time gives me enough time to fix little issues like this.
i have kombuster it that's any good for stress testing?

 

[red eye]

no BSOD just restarts with "windows was not shut down properly". The cooler is on properly temps are around 23 at idle and 38 when I exit a game

I ran furmark and gpu is a steady 60 degrees fans at 53%. prime lock up during test so I set auto oc back to normal and I been playing for a few hours and im now getting bits on the screen and mini map flashing(artifacts?) I tried to take a pic but it didt work